The Bioidentical Hormone Debate: Are Bioidentical Hormones (Estradiol, Estriol, and Progesterone) Safer or More Efficacious than Commonly Used Synthetic Versions in Hormone Replacement Therapy?

  title={The Bioidentical Hormone Debate: Are Bioidentical Hormones (Estradiol, Estriol, and Progesterone) Safer or More Efficacious than Commonly Used Synthetic Versions in Hormone Replacement Therapy?},
  author={Kent Holtorf},
  journal={Postgraduate Medicine},
  pages={73 - 85}
  • K. Holtorf
  • Published 1 January 2009
  • Biology, Medicine
  • Postgraduate Medicine
Abstract Background: The use of bioidentical hormones, including progesterone, estradiol, and estriol, in hormone replacement therapy (HRT) has sparked intense debate. Of special concern is their relative safety compared with traditional synthetic and animal-derived versions, such as conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), and other synthetic progestins. Proponents for bioidentical hormones claim that they are safer than comparable synthetic and nonhuman versions… 
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Bioidentical hormone therapy.
Compounded bioidentical HT is defined and the similarities and differences between it and US Food and Drug Administration-approved HT are explored.
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The study has proven that trans dermal application of compounded progesterone and bi estrogen cream can increase the serum levels of progester one and estradiol while at the same time improves the menopause syndromes.
Understanding bioidentical hormones and their effect on quality of life
The main functions of these hormones and how hormone imbalances can affect a patient's quality of life are highlighted, the importance of lifestyle and diet and the differences in treatment in different countries and the meaning of compounding are highlighted.
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If HT is to be used, it is proposed it be initiated immediately after cessation of ovarian hormone production and dosed as transdermal oestradiol combined with cyclic dosing of human-identical progesterone (P4).
Beneficial aspect of oral estriol as hormone replacement therapy: consideration on bone and lipid metabolism.
In the clinical management of postmenopausal women, oral E3 preparation as an alternative regimen for HRT for CEE might be efficacious, and lipid and bone metabolism were confirmed to be improved.
Effectiveness of Compounded Bioidentical Hormone Replacement Therapy: An Observational Cohort Study
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Hormone Therapy and Breast Cancer: Emerging Steroid Receptor Mechanisms.
Examples of hormone therapy used for the relief of menopausal symptoms are discussed, highlighting the distinction between conventional hormone therapy and custom-compounded bioidentical hormone therapy, and the fact that not all hormones have been evaluated for an association with increased breast cancer risk is highlighted.


Comparison of the proliferative effects of estradiol and conjugated equine estrogens on human breast cancer cells and impact of continuous combined progestogen addition
The results indicate that equine estrogens have a proliferative action similar to that of 17β-estradiol, and progesterone has no deleterious effect even at pharmacological levels, in contrast to progestogens.
Effects of estradiol with micronized progesterone or medroxyprogesterone acetate on risk markers for breast cancer in postmenopausal monkeys
Oral micronized progesterone has a more favorable effect on risk biomarkers for postmenopausal breast cancer than medroxyprogesterone acetate, and both progestogens significantly attenuated E2 effects on body weight, endometrium, and the TFF1 marker of estrogen receptor activity in the breast.
Pregnancy, progesterone and progestins in relation to breast cancer risk
Effect of norethisterone acetate on estrogen metabolism in postmenopausal women.
  • H. Seeger, A. Mueck, T. Lippert
  • Medicine, Biology
    Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme
  • 2000
Transdermal NETA in HRT did not elicit any change in estrogen metabolism after 2 weeks' treatment, but oral NETA may in some cases have an impact on estradiol metabolism which should be further evaluated.
Effects of oral and transdermal estrogen/progesterone regimens on blood coagulation and fibrinolysis in postmenopausal women. A randomized controlled trial.
Oral estrogen/progesterone replacement therapy may result in coagulation activation and increased fibrinolytic potential, whereas opposed transdermal estrogen appears without any substantial effects on hemostasis.
Differential Effects of Oral and Transdermal Estrogen/Progesterone Regimens on Sensitivity to Activated Protein C Among Postmenopausal Women: A Randomized Trial
The data show that oral, unlike transdermal, estrogen induces APC resistance and activates blood coagulation, and emphasize the importance of the route of estrogen administration.
Hormone replacement therapy with estrogen or estrogen plus medroxyprogesterone acetate is associated with increased epithelial proliferation in the normal postmenopausal breast.
It is shown that postmenopausal HRT with E+P was associated with greater breast epithelial cell proliferation and breast epithelium density than E alone or no HRT, and breast proliferation was localized to the terminal duct-lobular unit of the breast, which is the site of development of most breast cancers.
Hormone replacement therapy and risk of breast cancer: the role of progestins
Recent studies originating from both the USA and Europe suggest that the combined treatment regimens with estrogen and progestin increase the risk of breast cancer beyond the risk following the use of unopposed estrogen.
Estrogen–progestin replacement therapy and breast cancer risk: the Women's Health Study (United States)
Use of estrogen–progestin replacement therapy imparts an increased risk of breast cancer in comparison with never use of PMH, and higher doses of estrogen, but not progestin, were associated with increased breast cancer risk, compared with lower doses.